Determination of Selenium Traces on Cyclic Renewable Mercury Film Silver Electrode in Presence of Copper Ions Using Cathodic Stripping Voltammetry

The new cyclic renewable mercury film silver based electrode (Hg(Ag)FE), applied for the determination of selenium(IV) traces in the presence of copper ions using differential pulse cathodic stripping voltammetry (DP CSV) is presented. The preparation of the Hg(Ag)FE is very simple. The effects of various factors such as: preconcentration potential and time, pulse height, step potential and Supporting electrolyte composition are optimized. The calibration graph is linear from 0.5 nM (39 ng L(-1)) to 100 nM (7.9 mu g L(-1)) for a preconcentration time of 45 s, with correlation coefficient of 0.9995. For a Hg(Ag)FE with a surface area of 8 mm(2) the detection limit for a preconcentration time of 90 s is as low as 17 ng L(-1). The repeatability of the method at a concentration level of the analyte as low as 2 mu g L(-1). expressed as RSD is 2.7% (n = 7). The proposed method was successfully applied and validated by studying the certified reference material (bovine liver BCR-185) and simultaneously recovery of Se(IV) from spiked water samples.